CN100442914C - User equipment link management method in soft handover area - Google Patents

Abstract

The invention relates to mobile communication technology, and discloses a user equipment link management method in a soft handover area, so that UEs staying in the soft handover area for a long time can use less resources to perform high-speed services. In the present invention, the time the UE stays in the soft handover area is monitored. If it exceeds a predetermined threshold and has a link with better quality, only one link with better quality is reserved for the UE, and other links in the active set are released. link, mark the UE as staying in the soft handover area. In addition, for a UE staying in the soft handover area, the UE is allowed to return to the normal soft handover state only when the signal quality of the current cell deteriorates to a certain extent or a cell with much better signal quality than the current cell appears.

Description

User equipment link management method in soft handover area

technical field

The invention relates to mobile communication technology, in particular to soft handoff technology in wideband code division multiple access system.

Background technique

With the development of high technology marked by communication technology and computer technology, people's lives have undergone tremendous changes with each passing day, and the information transmission between people is getting closer and more diverse. The development of cellular mobile communication has brought great convenience to users. At present, its development has gone through three generations. They are the first generation based on Frequency Division Multiple Access (FDMA) technology in the early 1980s. Analog mobile communication system, the second-generation digital cellular mobile communication system based on Time Division Multiple Access (TDMA) technology in the early 1990s, and the current new generation of mobile and personal communication systems, namely Code Division Multiple Access (CDMA) technology-based third-generation mobile and personal communication systems. The research and development of the third-generation mobile and personal communication systems has become a hot spot in the field of telecommunications, and three major world standards have been formed, among which Wideband Code Division Multiple Access ("WCDMA") is the most promising One of the techniques.

The WCDMA system includes two parts: Radio Access Network ("RAN" for short) and Core Network ("CN" for short). Among them, the RAN mainly includes two types of nodes: a base station (NodeB) and a radio network controller (Radio Network Controller, referred to as "RNC"). NodeB is used for sending and receiving wireless signals and underlying processing, such as modulation and demodulation, encoding and decoding, etc. The RNC is used for management of radio resources in the air, for example, sending cell broadcasts, allocating radio channels, configuring cell parameters, managing radio access bearers between the mobile phone and the system, and so on. Each NodeB node receives the signal of mobile phone users within its jurisdiction, and after processing, summarizes it to the RNC through the transmission channel. The RNC centrally processes the information transmitted by each NodeB node, and sends the processed information to the mobile phone through these NodeB nodes.

In the WCDMA system, handover is a key technology to support users' global roaming. It is an important mobility management function unique to the cellular system, and it directly affects the performance of the entire system. The so-called handover is when the mobile station (Mobile Station, referred to as "MS") moves from one cell to another during the call; or the call quality is degraded due to external interference; or because there are too many users in a cell, it is impossible to guarantee all When the user uses it normally, the MS must switch the communication service to a new channel and continue to maintain communication. The link between the original base station and the MS will possibly be replaced by a link between the new base station and the MS. There are many classification methods for handover types. According to the connection establishment and release between the MS and the network, it can be divided into softer handover, soft handover and hard handover. What the present invention relates to is the soft handover technology.

Soft handover means that when the mobile station needs to communicate with a new base station, it does not interrupt the connection with the original base station first. However, the previous systems all performed hard handoffs, that is, they first interrupted the connection with the original base station, and then contacted the new base station within a specified time. Soft handover can only be performed between CDMA channels of the same frequency. It plays the role of diversity of traffic channels at the junction of two base station coverage areas. This can greatly reduce the dropped calls caused by switching. Because according to the test statistics of the analog system TDMA in the past, 90% of the dropped calls on the wireless channel occurred during the switching process. After soft handover is realized, the probability of call drop caused by handover is greatly reduced, which ensures the reliability of communication.

However, just because the connection with the original base station will not be interrupted during soft handover, that is, multiple links are established with the new base station and the original base station at the same time, it will inevitably cause the UE in the soft handover state to occupy more resources and affect the system capacity, especially for users. When performing high-speed services, system resources are greatly wasted. However, this problem is particularly prominent for those who stay in the soft handover area for a long time, or stay in the soft handover area all the time.

At present, in order to solve this problem, a commonly used solution is to reduce the bandwidth of the high-speed service that the user is performing before entering the soft handover state, and restore the user's bandwidth according to the actual situation of the user's traffic request after leaving the soft handover state.

However, in the case of staying in the soft handover area for a long time after entering the soft handover area, or staying in the soft handover area all the time, the above solution will cause the user in the above state to be unable to perform high-speed services for a long time.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a user equipment link management method in a soft handover area, so that UEs staying in the soft handover area for a long time can use less resources to perform high-speed services.

In order to achieve the above object, the present invention provides a user equipment link management method in a soft handover area, comprising the following steps:

The A network side records the time that the user equipment maintains the soft handover state, and judges whether the time exceeds the preset first threshold, and if so, checks the signal quality of all links in the current active set of the user equipment;

B judges whether there is at least one link whose signal quality is better than the preset second threshold, and if so, selects one of them to reserve, and releases other links in the active set.

Wherein, in the step B, the link with the best signal quality may be selected to be reserved.

In addition, in the method, in the step B, the link to be reserved can be determined according to one of the following factors or any combination thereof:

Signal quality, coverage of the cell to which the link belongs, and load of the cell to which the link belongs.

In addition, in the method, the step B further includes the following sub-steps:

After releasing other links in the active set, mark the user equipment as staying in the soft handover area, and modify the same-frequency measurement control information in the user equipment as soft handover staying cell measurement control information, wherein the soft handover staying cell measurement control information The control information instructs the user equipment to report a measurement report when one of the following conditions is met:

The signal quality of the current cell is lower than the preset third threshold;

The signal quality of other cells is higher than a fourth threshold, where the fourth threshold is higher than the third threshold.

In addition, the method also includes the following steps:

For a user equipment staying in the soft handover area, when the network side receives a measurement report that the signal quality of the current cell is lower than the third threshold, clear the user equipment staying in the soft handover area and restore the same-frequency measurement control information .

In addition, in the method, the value of the fourth threshold may be a preset fixed value, or the signal quality of the current cell plus a preset fixed value.

In addition, the method also includes the following steps:

For the user equipment staying in the soft handover area, when the network side receives the measurement report that the signal quality of other cells is higher than the fourth threshold, the soft handover process is retriggered and the intra-frequency measurement control information is restored.

In addition, in the method, the step A includes the following sub-steps:

When entering the soft handover process, the user equipment starts a timer after reporting the active set update completion message, and the duration of the timer is the first threshold;

When the user equipment leaves the soft handover area, stop the timer;

When the timer expires, check the signal quality of all links in the current active set of the user equipment, and proceed to step B.

Through comparison, it can be found that the main difference between the technical solution of the present invention and the prior art is that the time the UE stays in the soft handover area is monitored. If it exceeds a predetermined threshold and has a link with better quality, only the A link with better quality is given to the UE, other links in the active set are released, and the UE is marked as staying in the soft handover area. In addition, for a UE staying in the soft handover area, the UE is allowed to return to the normal soft handover state only when the signal quality of the current cell deteriorates to a certain extent or a cell with much better signal quality than the current cell appears.

This difference in technical solutions has brought obvious beneficial effects, that is, for UEs staying in the soft handover area and having high-quality links, because it provides a method for accurately identifying such UEs, and only reserves them for this UE. An optimal link is established, so it can not only ensure the normal communication of the UE with high quality (such as using high-speed data services), but also ensure that there is no unnecessary waste of resources on the network side. Moreover, since the soft handover link increase request initiated by the UE staying in the soft handover area is restricted, resource waste can be better prevented.

Description of drawings

Fig. 1 is a schematic flowchart of a method for link management of user equipment in a soft handover area according to a first embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in FIG. 1, the UE link management method in the soft handover area according to the first embodiment of the present invention includes the following processes and steps:

First, the network side records the time that the UE stays in the soft handover state, and judges whether the time exceeds the preset first threshold. If so, it indicates that the UE has stayed in the soft handover area for a long time, or has been in the soft handover area. In this case, it is further checked whether the signal quality of all links in the current active set of the UE exceeds the preset second threshold. Specifically, this process corresponds to steps 110 to 130 in Figure 1:

In step 110, the soft handover procedure is entered, and after the UE reports the update completion message of the active set, a timer is started, and the duration of the timer is the above-mentioned first threshold.

In step 120, it is judged whether the UE leaves the soft handover area before the timer expires, and if so, proceed to step 190, stop the timer, and the process ends; otherwise, proceed to step 130.

In step 130, check the signal quality of all links in the current active set of the UE, and determine whether there is at least one link whose signal quality is better than a preset second threshold among all the links in the current active set. If yes, go to step 140, otherwise, the process ends.

Afterwards, if there is at least one link whose signal quality is better than the preset second threshold among all the links in the current active set, then according to a rule, one of them is selected to be reserved, and other links in the active set are released. Next, mark the UE as staying in the soft handover area, and modify the intra-frequency measurement control information in the UE to soft handover staying cell measurement control information. The soft handover staying cell measurement control information is used to indicate that the signal quality of the UE in the current cell is lower than the preset If the third threshold is set or the signal quality of other cells is higher than the fourth threshold, a measurement report is reported. Wherein, the fourth threshold is higher than the third threshold, and the value of the fourth threshold may be a preset fixed value, or the signal quality of the current cell plus a preset fixed value.

If it corresponds to the steps in FIG. 1 , the above process corresponds to step 140 to step 150 .

In step 140, select the optimal link from all the links in the current active set to reserve, release the remaining links, and record that the UE is staying in the soft handover area. It should be pointed out that, in the present invention, although the link with the best signal quality is selected and reserved in this embodiment. However, in other embodiments of the present invention, the link to be reserved may also be determined according to one factor among the signal quality, the coverage of the cell to which the link belongs, and the load of the cell to which the link belongs, or a combination of their tasks.

In step 150, the intra-frequency measurement control information is modified as the soft handover remaining cell measurement control information for instructing the UE to report the above measurement report.

Next, when the measurement report is received, the type of the measurement report is judged, and the following processing is performed according to the judgment result: if the measurement report indicates that the signal quality of the current cell is lower than the third threshold, the soft handover area stay status of the UE is cleared, and the same frequency is restored. Measurement control information. If the measurement report indicates that the signal quality of other cells is higher than the measurement report of the fourth threshold, the soft handover process is retriggered, and the intra-frequency measurement control information is restored.

Specifically, the above process corresponds to step 160 to step 180 in FIG. 1 .

In step 160, keep the current state until the measurement report is received, judge the report type, if the report indicates that the signal quality of the current cell is lower than the preset third threshold, then enter step 180, if the report indicates that the signal quality of other cells is high At the fourth threshold, go to step 170 .

In step 170, clear the UE's soft handover area staying status flag, re-trigger the soft handover process, and restore normal measurement control information.

In step 180, clear the UE's staying state flag in the soft handover area, and restore normal measurement control information.

It can be seen that the present invention monitors the time that the UE stays in the soft handover area, and only keeps the link with better quality when the link with better quality exceeds the predetermined threshold. For UEs that stay in the handover area and have high-quality links, because a method for accurately identifying such UEs is provided, and only one optimal link is reserved for the UE, it can not only ensure that the UE communicates normally with high quality, but also It can ensure that there is no unnecessary resource waste on the network side. On the other hand, for a UE staying in the soft handover area, only when the signal quality of the current cell deteriorates to a certain extent or a cell with much better signal quality than the current cell appears, the UE is allowed to return to the normal soft handover state. Since the soft handover link increase request initiated by the UE staying in the soft handover area is restricted, resource waste can be better prevented.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the present invention. The spirit and scope of the invention.

Claims (8)

1. A user equipment link management method in a soft handover area, characterized in that, comprising the following steps: The A network side records the time that the user equipment maintains the soft handover state, and judges whether the time exceeds the preset first threshold, and if so, checks the signal quality of all links in the current active set of the user equipment; B judges whether there is at least one link whose signal quality is better than the preset second threshold, and if so, selects one of them to reserve, and releases other links in the active set. 2. The user equipment link management method in the soft handover area according to claim 1, characterized in that, in the step B, the link with the best signal quality is selected and reserved. 3. The user equipment link management method in the soft handover area according to claim 1, characterized in that, in the step B, the link to be reserved is determined according to one of the following factors or any combination thereof: Signal quality, coverage of the cell to which the link belongs, and load of the cell to which the link belongs. 4. The user equipment link management method in the soft handover area according to any one of claims 1 to 3, wherein the step B further comprises the following sub-steps: After releasing other links in the active set, mark the user equipment as staying in the soft handover area, and modify the same-frequency measurement control information in the user equipment as soft handover staying cell measurement control information, wherein the soft handover staying cell measurement control information The control information instructs the user equipment to report a measurement report when one of the following conditions is met: The signal quality of the current cell is lower than the preset third threshold; The signal quality of other cells is higher than a fourth threshold, where the fourth threshold is higher than the third threshold. 5. the user equipment link management method in the soft handover area according to claim 4, is characterized in that, described method also comprises the following steps: For a user equipment staying in the soft handover area, when the network side receives a measurement report that the signal quality of the current cell is lower than the third threshold, clear the user equipment staying in the soft handover area and restore the same-frequency measurement control information . 6. The user equipment link management method in the soft handover area according to claim 4, wherein the value of the fourth threshold is a preset fixed value, or the signal quality of the current cell plus a preset value Fixed value. 7. The user equipment link management method in the soft handover area according to claim 6, wherein the method further comprises the following steps: For the user equipment staying in the soft handover area, when the network side receives the measurement report that the signal quality of other cells is higher than the fourth threshold, the soft handover process is retriggered and the intra-frequency measurement control information is restored. 8. The user equipment link management method in the soft handover area according to any one of claims 1 to 3, wherein the step A comprises the following sub-steps: When entering the soft handover process, the user equipment starts a timer after reporting the active set update completion message, and the duration of the timer is the first threshold; When the user equipment leaves the soft handover area, stop the timer; When the timer expires, check the signal quality of all links in the current active set of the user equipment, and proceed to step B.

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